[found on adulted.about.com]

Me and Tim, Tim and I

• Wrong: Me and Tim are going to a movie tonight.
• Right: Tim and I are going to a movie tonight.

Why?

• If you take Tim out of the sentence, “you” are the subject.
• You are going to a movie. When you’re going to a movie, what do you say?
  • “I am going to a movie.”
  • You wouldn’t say, “Me am going to a movie.”

• When you add Tim, the sentence construction remains the same.
• You’re simply adding Tim, and it’s correct to say the other person’s name first.
  • “Tim and I are going to a movie.”

[found on http://adulted.about.com/od/howtos/tp/fivegrammartips.htm]